The Bulletin. 



53 



by not planting tobacco in a field which has lain in sod for some 

 time. Fall plowing will aid somewhat in killing Wireworms which 

 may be in the soil already. 



Remedies.' — All sorts of methods have been used against Wireworms, 

 but most of these have not been successful. No method of dipping 

 the plants or soaking the seed in any sort of foul-smelling substance 

 seems to prevent the attacks of these pests. 



Tobacco Leaf Miner. 1 



Also Known as "Split Worm." 



(Order Lepidoptera.) 



Large irregular blotches appearing on the leaves. These are at first 

 whitish, but later become very dry and parchment-like. Upon ex- 

 amination it will be found that the interior of the leaf has been en- 

 tirely eaten away, leaving only the upper and lower surfaces. This 

 trouble seems to be confined to areas along the principal veins and 

 along the mid-rib. (Fig. 40.) Leaves injured in this way are 

 unfit for wrapper purposes, as they tear very easily. 



Life-histories and Habits. — The adult moth which lays the eggs that 

 develop into the leaf miner is a yellowish-gray insect belonging to the 

 same group and closely resembling the common clothes moth. (Fig. 

 41.) Its wings measure when fully expanded about half an inch 



Fig. 41.— Adult of the Tobacco Leaf Miner, enlarged. 

 {Redrawn from McCarthy.) 



across. The adult places its eggs upon the leaves of its food plant. 

 The young larvse (Fig. 42) on hatching eat directly into the leaf. 

 Once on the inside of the leaf, it commences to eat out the tender inner 

 portions between the upper and lower surfaces of the leaf. As pointed 

 out by Quaintance, the larva does not confine its attention to one spot 

 in the leaf, but moves from place to place. In this way one larva 

 will be responsible for several blotches. The larva? when full-grown 



l I'hthorimaea operculella. 



